Simultaneous maneuver and vibration suppression of flexible spacecraft

A method is described for the simultaneous large-angle maneuver and vibration suppression of flexible spacecraft. The control action is carried out in two independent systems, one system performing the maneuvers and the other system controlling the elastic motion. The vibration is suppressed using a natural control. It is shown that control of the elastic motion does not distort the maneuver because the spacecraft linear and angular momenta are conserved regardless of spacecraft modeling errors. Thus, the maneuver can be designed and performed independently of the elastic motion control.     

Optimal vibration control of flexible spacecraft during a minimum-time maneuver

This paper is concerned with the simultaneous maneuver and vibration control of a flexible spacecraft. The problem is solved by means of a perturbation approach whereby the slewing of the spacecraft regarded as rigid represents the zero-order problem and the control of vibration, as well as of perturbations from the rigid-body maneuver, represents the first-order problem. The zero-order control is to be carried out in minimum time, which implies bang-bang control. On the other hand, the first-order control is a time-dependent linear quadratic regulator including integral feedback and prescribed convergence rate.This research was sponsored by USAF/ASD and AFOSR Research Grant F33615-86-C-3233 monitored by Drs. A. K. Amos and V. B. Venkayya, whose support is greatly appreciated.